Repeat a string

Take a string and repeat it some number of times. Example: repeat("ha", 5) => "hahahahaha"

Repeat a string
You are encouraged to solve this task according to the task description, using any language you may know.

Ada

In Ada multiplication of an universal integer to string gives the desired result. Here is an example of use: <lang Ada>with Ada.Strings.Fixed; use Ada.Strings.Fixed; with Ada.Text_IO; use Ada.Text_IO;

procedure String_Multiplication is begin

  Put_Line (5 * "ha");

end String_Multiplication;</lang> Sample output:

hahahahaha

C

<lang c>#include <stdio.h>

1. include <stdlib.h>
2. include <string.h>

char * string_repeat( int n, const char * s ) {

 size_t slen = strlen(s);
 char * dest = (char *)calloc(n*slen, sizeof(char));

 int i; char * p;
 for ( i=0, p = dest; i < n; ++i, p += slen ) {
   memcpy(p, s, slen);
 }
 return dest;

}

int main() {

 printf("%s\n", string_repeat(5, "ha"));

}</lang>

C++

<lang cpp>#include <string>

1. include <iostream>

std::string repeat( const std::string &word, int times ) {

  std::string result ;
  result.reserve(times*word.length()); // avoid repeated reallocation
  for ( int a = 0 ; a < times ; a++ ) 
     result += word ;
  return result ;

}

int main( ) {

  std::cout << repeat( "Ha" , 5 ) << std::endl ;
  return 0 ;

}</lang>

C#

<lang csharp> String s = "".PadLeft(5, 'X').Replace("X", "ha")</lang>

Clojure

<lang lisp>(apply str (repeat 5 "ha"))</lang>

E

<lang e>"ha" * 5</lang>

Forth

<lang forth>: place-n { src len dest n -- }

 0 dest c!
 n 0 ?do src len dest +place loop ;

create test 256 allot s" ha" test 5 place-n test count type \ hahahahaha</lang>

Fortran

Works with: Fortran version 90 and later

<lang fortran>program test_repeat

 write (*, '(a)') repeat ('ha', 5)

end program test_repeat</lang> Output:

hahahahaha

Haskell

For a string of finite length:

<lang haskell>concat $ replicate 5 "ha"</lang>

For an infinitely long string:

<lang haskell>cycle "ha"</lang>

J

<lang j> 5 ((* #) $ ]) 'ha' hahahahaha</lang>

Java

Works with: Java version 1.5+

There's no function or operator to do this in Java, so you have to do it yourself. <lang java5>public static String repeat(String str, int times){

  StringBuilder ret = new StringBuilder();
  for(int i = 0;i < times;i++) ret.append(str);
  return ret.toString();

}

public static void main(String[] args){

 System.out.println(repeat("ha", 5));

}</lang>

Or even shorter: <lang java5>public static String repeat(String str, int times){

  return new String(new char[times]).replace("\0", str);

}</lang>

JavaScript

This solution creates an array of n+1 null elements, then joins them using the target string as the delimiter <lang javascript>String.prototype.repeat = function(n) {

   return new Array(1 + parseInt(n, 10)).join(this);

}

alert("ha".repeat(5)); // hahahahaha</lang>

Logo

<lang logo>to copies :n :thing [:acc "||]

 if :n = 0 [output :acc]
 output (copies :n-1 :thing combine :acc :thing)

end</lang> or using cascade: <lang logo>show cascade 5 [combine "ha ?] "||  ; hahahahaha</lang>

OCaml

<lang ocaml>let string_repeat s n =

 let len = String.length s in
 let res = String.create(n * len) in
 for i = 0 to pred n do
   String.blit s 0 res (i * len) len;
 done;
 (res)

</lang>

testing in the toplevel: <lang ocaml># string_repeat "Hiuoa" 3 ;; - : string = "HiuoaHiuoaHiuoa"</lang>

Alternately: <lang ocaml>let string_repeat s n =

 String.concat "" (Array.to_list (Array.make n s))

</lang>

Or: <lang ocaml>let string_repeat s n =

 Array.fold_left (^) "" (Array.make n s)

</lang>

Oz

We have to write a function for this: <lang oz>declare

 fun {Repeat Xs N}
    if N > 0 then
       {Append Xs {Repeat Xs N-1}}
    else
       nil
    end
 end

in

 {System.showInfo {Repeat "Ha" 5}}</lang>

Perl

<lang perl>"ha" x 5</lang>

Perl 6

Works with: Rakudo version #21 "Seattle"

<lang perl6>"ha" x 5</lang>

(Note that the x operator isn't quite the same as in Perl 5: it now only creates strings. To create lists, use xx.)

PHP

<lang php>str_repeat("ha", 5)</lang>

PowerBASIC

<lang powerbasic>MSGBOX REPEAT$(5, "ha")</lang>

Pure

str_repeat is defined by pattern-matching: repeating any string 0 times results in the empty string; while repeating it more than 0 times results in the concatenation of the string and (n-1) further repeats.

<lang pure>> str_repeat 0 s = ""; > str_repeat n s = s + (str_repeat (n-1) s) if n>0; > str_repeat 5 "ha"; "hahahahaha" ></lang>

Python

<lang python>"ha" * 5 # ==> "hahahahaha"</lang>

PowerShell

<lang powershell>"ha" * 5 # ==> "hahahahaha"</lang>

Ruby

<lang ruby>"ha" * 5 # ==> "hahahahaha"</lang>

Scala

<lang scala>"ha" * 5 // ==> "hahahahaha"</lang>

Scheme

<lang scheme>(define (string-repeat n str) (fold string-append "" (make-list n str))) (string-repeat 5 "ha") ==> "hahahahaha"</lang>

Tcl

<lang tcl>string repeat "ha" 5  ;# => hahahahaha</lang>

Ursala

<lang Ursala>#import nat

repeat = ^|DlSL/~& iota

1. cast %s

example = repeat('ha',5)</lang> output:

'hahahahaha'